Navegando por Assunto "Cromatografia"

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Acesso aberto (Open Access)
Active polyketides isolated from Penicillium herquei
(2013-09) MARINHO, Andrey Moacir do Rosário; MARINHO, Patrícia Santana Barbosa; SANTOS, Lourivaldo da Silva; RODRIGUES FILHO, Edson; FERREIRA, Izabel Cristina Piloto
In this work we are reporting the isolation by classical methods of chromatography of six polyketides from Penicillium herquei. The compounds citreorosein ( 1) , emodin ( 2) , janthinone ( 3) , citrinin ( 4) , citrinin H1 ( 5) and dicitrinol ( 6) were identified by spectral methods of 1D and 2D NMR and MS. Compounds 1, 2 and 3 were tested against promastigotes forms of Leishmania brasiliensis and 1 and 2 were also assayed against Escherichia coli, Pseudomonas aeruginosa and Bacillus subtilis and showed good activity.
Acesso aberto (Open Access)
Análises cromatográficas por CLAE-DAD, termogravimétricas e morfo-anatômicas de amostras comerciais de Echinodorus macrophyllus (Kunth) Micheli (Chapéu-de-couro)
(Universidade Federal do Pará, 2010) FREITAS, Cristian Barbosa de; BORGES, Fernanda Iikiu; BARBOSA, Wagner Luiz Ramos; http://lattes.cnpq.br/1372405563294070
For quality control of the commercial sample of Echinodorus macrophyllus were analyzed with botanical, pharmacognostic and physical-chemical properties. To achieve the anatomical cuts was rehydrated, sectioned with steel blade and fixed on slides semi-permanent. The sections were cleared in 20% NaClO and stained with astra blue-to-follow basic fuchsin. In cross section the epidermis is uniseriate with cells of rectangular shapes, heterodimensional, smooth and thin cuticle. For realization of thermogravimetry was used both drugs as solids at a heating rate of 5, 10 and 15 degrees Celsius. The chromatography was performed in HPLC and sample was obtained from column chromatography and eluted by gradient with methanol and acidic water. The palisade tissue consists of two layers of cells. The parenchyma spongy cells have thin walls, heterodimensional, different formats and well-developed intercellular spaces. The vascular bundles are collateral. The leaf is amphistomatic with stomata paracytic. Petiole in cross section, has a triangular to hexagonal. The epidermis is uniseriate with cells of polygonal shape, smooth walls, large amounts of aerenchyma which sometimes occur diaphragms. Samples of the leaf have characteristics of the species E. macrophyllus, but the anatomy of the petiole showed different structures from those described for the species, which belong to the genus Echinodorus, however suggests possible contamination of the material supplied with other plant species. Thermogravimetric analysis contributed significantly to establish parameters and characterize the sample.
Acesso aberto (Open Access)
Desenvolvimento de métodos por CL-EM/Em e ocorrência de antimicrobianos em peixes de aquicultura
(Universidade Federal do Pará, 2016-11-22) GUIDI, Letícia Rocha; GLÓRIA, Maria Beatriz de Abreu; http://lattes.cnpq.br/6895373188728113; SILVA, Luiza Helena Meller da; http://lattes.cnpq.br/2311121099883170
The consumption of fish has increased in recent years in Brazil, especially due to the announcement that their intake can bring numerous health benefits and also due to its high nutritional value (high biological value protein, high content of omega-3 fatty acids). The quality, safety and security of farmed fish for human consumption are therefore a public health issue and must be monitored. In Brazil, there is a lack of information regarding the use of antimicrobials in aquaculture. Although only two antibiotics are allowed for use in aquaculture in Brazil, there is a wide variety of antibiotics that may be used illegally or can reach the fish due to environmental contaminations, mainly of water. The objective of this study was to develop multiresidue methods of analysis of antibiotics in fish muscle and to evaluate the quality of fish from Minas Gerais and Pará with respect to the presence of antibiotic residues. In addition, an extensive literature review was conducted with respect to existing methods of analysis and the occurrence of chloramphenicol (banned antibiotic) and amphenicols in food. A LC-MS/MS screening method was validated for the analysis of 40 antibiotics of six different classes (aminoglycosides, beta-lactams, macrolides, quinolones, sulfonamides and tetracyclines) in fish muscle. Only 15% of the samples (n=29) were positive for enrofloxacin. A quantitative LC-MS/MS method of analysis of quinolones and tetracyclines in fish muscle was also optimized and validated. The precision, in terms of the relative standard deviation, was under 20% for all of the compounds, and the recoveries were between 89.3% and 103.7%. CCα varied from 17.87 to 323.20 μg.kg-1 and CCβ varied from 20.75 to 346.40 μg.kg-1. In general, real samples showed good quality relative to the presence of antibiotic residues. All 29 positive samples for enrofloxacin contained levels below the Maximum Residue Limit allowed by Brazilian legislation (100 μg.kg-1).
Acesso aberto (Open Access)
Relationship between plasma and red blood cell concentrations of quinine in Brazilian children with uncomplicated Plasmodium falciparummalaria on oral therapy
(2009-04) VIEIRA, José Luiz Fernandes; GOMES, Andreza de Lourdes Souza; BORGES, Larissa Maria Guimarães; GUIMARÃES, Erika Rodrigues
We determined the relationship between plasma and red blood cell concentrations of quinine in children with uncomplicated falciparum malaria from an endemic area of Amazonian region. Quinine was determined by high performance liquid chromatography with ultraviolet detection. In the steady state the ratio between plasma and red blood cell quinine concentration was 1.89 ± 1.25 ranging from 1.05 to 2.34. This result demonstrated that quinine do not concentrate in red blood cell of Brazilian children and characterize the absence of interracial difference in this relationship.